首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   16841篇
  免费   934篇
  国内免费   84篇
耳鼻咽喉   259篇
儿科学   338篇
妇产科学   280篇
基础医学   2438篇
口腔科学   1749篇
临床医学   1333篇
内科学   3468篇
皮肤病学   396篇
神经病学   1225篇
特种医学   444篇
外科学   1790篇
综合类   49篇
一般理论   4篇
预防医学   1936篇
眼科学   168篇
药学   1270篇
中国医学   176篇
肿瘤学   536篇
  2023年   148篇
  2022年   424篇
  2021年   633篇
  2020年   428篇
  2019年   553篇
  2018年   675篇
  2017年   533篇
  2016年   511篇
  2015年   679篇
  2014年   814篇
  2013年   930篇
  2012年   1407篇
  2011年   1571篇
  2010年   831篇
  2009年   625篇
  2008年   1001篇
  2007年   1020篇
  2006年   815篇
  2005年   702篇
  2004年   594篇
  2003年   496篇
  2002年   414篇
  2001年   266篇
  2000年   253篇
  1999年   197篇
  1998年   93篇
  1997年   84篇
  1996年   68篇
  1995年   58篇
  1994年   73篇
  1993年   44篇
  1992年   88篇
  1991年   90篇
  1990年   61篇
  1989年   71篇
  1988年   65篇
  1987年   43篇
  1986年   55篇
  1985年   47篇
  1984年   30篇
  1983年   37篇
  1982年   21篇
  1981年   18篇
  1980年   31篇
  1979年   31篇
  1977年   17篇
  1975年   18篇
  1973年   20篇
  1970年   16篇
  1968年   32篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
Lasers in Medical Science - Using light sources in phototherapy has presented promising results regarding several types of facial and body skin affections for centuries. The neodymium-doped yttrium...  相似文献   
12.
Recently, there has been a call for research-informed and research-developed practice in health sciences education. This prompts the consideration of alternative suitable research approaches that could be used to enhance health sciences education practice, including medical radiation sciences education (MRSE) practice. In this discussion paper, the authors uphold design science research (DSR) methodology as a suitable research approach to enhance MRSE practice and research. An overview of the DSR methodology and an example of a project that used DSR methodology are presented to demonstrate the application of this methodology in MRSE practice and research. The paper concludes that the use of DSR methodology could be instrumental in addressing practice related challenges while developing a theoretical contribution to the discipline.  相似文献   
13.
14.
15.
16.
17.
18.
This case report demonstrates how extracting a maxillary deciduous canine affects the eruption path of a labially displaced ectopically erupting permanent canine. A long-term follow-up is presented, and the biologic mechanisms are discussed.  相似文献   
19.
Atrial electrical remodeling plays a part in recurrence of atrial fibrillation (AF). It has been related to an increase in heterogeneity of atrial refractoriness that facilitates the occurrence of multiple reentry wavelets and vulnerability to AF. AIM: To examine the relationship between dispersion of atrial refractoriness (Disp_A) and vulnerability to AF induction (A_Vuln) in patients with clinical paroxysmal AF (PAF). METHODS: Thirty-six patients (22 male; age 55+/-13 years) with > or =1 year of history of PAF (no underlying structural heart disease--n=20, systemic hypertension--n=14, mitral valve prolapse--n=1, surgically corrected pulmonary stenosis--n=1), underwent electrophysiological study (EPS) while off medication. The atrial effective refractory period (AERP) was assessed at five different sites--high (HRA) and low (LRA) lateral right atrium, high interatrial septum (IAS), proximal (pCS) and distal (dCS) coronary sinus--during a cycle length of 600 ms. AERP was taken as the longest S1-S2 interval that failed to initiate a propagation response. Disp_A was calculated as the difference between the longest and shortest AERP. A_Vuln was defined as the ability to induce AF with 1-2 extrastimuli or with incremental atrial pacing (600-300 ms) from the HRA or dCS. The EPS included analysis of focal electrical activity based on the presence of supraventricular ectopic beats (spontaneous or with provocative maneuvers). The patients were divided into group A--AF inducible (n=25) and group B--AF not inducible (n=11). Disp_A was analyzed to determine any association with A_Vuln. Disp_A and A_Vuln were also examined in those patients with documented repetitive focal activity. Logistic regression was used to determine any association of the following variables with A_Vuln: age, systemic hypertension, left ventricular hypertrophy, left atrial size, left ventricular function, duration of PAF, documented atrial flutter/tachycardia and Disp_A. RESULTS: There were no significant differences between the groups with regard to clinical characteristics and echocardiographic data. AF was inducible in 71% of the patients and noninducible in 29%. Group A had greater Disp_A compared to group B (105+/-78 ms vs. 49+/-20 ms; p=0.01). Disp_A was >40 ms in 50% of the patients without A_Vuln and in 91% of those with A_Vuln (p=0.05). Focal activity was demonstrated in 14 cases (39%), 57% of them with A_Vuln. Disp_A was 56+/-23 ms in this group and 92+/-78 ms in the others (p=0.07). Using logistic regression, the only predictor of A_Vuln was Disp_A (p=0.05). CONCLUSION: In patients with paroxysmal AF, Disp_A is a major determinant of A_Vuln. Nevertheless, the degree of nonuniformity of AERP appears to be less important as an electrophysiological substrate for AF due to focal activation.  相似文献   
20.
A 28-month-old boy, weighing 11 kg, with severe dilated cardiomyopathy, was transplanted on December 1995. Hypertension and supraventricular tachycardia were detected in the immediate post-operative period, with favorable outcome. After 5 months of clinically asymptomatic follow-up, a dilation in the ascending aorta was observed on routine echocardiogram. Nuclear magnetic resonance imaging (NMRI) confirmed an ascending aortic aneurysm, with a diameter of 38 mm. An operation was performed, a bovine pericardium patch was sutured with reconstruction of the aortic wall, excluding the aneurysm. Good recovery was obtained and the child was discharged on Day 7 postoperatively. A post-operative echocardiogram showed absence of the aortic aneurysm and good surgical results. Another NMRI was done 5 months later, showing an intact ascending aorta. After 64 months, the patients clinical condition was confirmed as normal by echocardiogram. Surgical treatment was successful and the positive results have been maintained.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号